* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

li {
    list-style: none;
}

.box {
    position: relative;
    width: 100%;
    height: 737px;
    overflow: hidden;
    border-radius: 25px;
}

.box ul {
    display: flex;
    width: calc(100% * 7);
    height: 100%;
}

.box ul li {
    float: left;
    width: 100%;
    height: 100%;
}

.box .prev,
.box .next {
    display: none;
    position: absolute;
    top: calc(50% - 33px);
    width: 66px;
    height: 66px;
    border-radius: 50%;
    background-color: rgba(0, 0, 0, 0.1);
    color: rgba(255, 255, 255, 0.5);
    font-size: 45px;
    transition: all 0.3s;
    cursor: pointer;
}

.box .prev {
    left: 45px;
    padding-left: 13px;
}

.box .next {
    right: 45px;
    padding-left: 19px;
}

.box .prev:hover,
.box .next:hover {
    background-color: #fc6060;
    color: rgb(255, 255, 255);
}

.nav {
    display: flex;
    width: 80%;
    margin: 25px auto;
    justify-content: center;
}

.nav ul li {
    float: left;
    margin: 0 25px;
    border-bottom: 4.1px solid transparent;
    font-weight: 700;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s;
}

/* 下划线样式 */
.nav ul li.active {
    border-bottom: 4.1px solid rgb(252, 96, 96);
}

.waterfall {
    position: relative;
    width: 95%;
    margin: 0 auto;

    display: flex;
    justify-content: center;
}

.waterfall img {
    position: absolute;
    width: 180px;
    margin: 2px;
    border-radius: 10px;
    transition: all 0.3s;
}

.addicon {
    width: 180px;
    height: 120px;
    font-size: 100%;
    color: #e0e0e0e0;
    background-image: url("add.svg");
}